DNA microarrays have emerged in just a few years as one of the most powerful approaches for assessing gene expression on a genome-wide scale. Despite its enormous potential, adoption of this technology by the neuroscience community has been slowed by the limited availability of microarrays, by limited access to training in microarray technologies, and by the extreme complexity and heterogeneity of cell types in the nervous system. At the same time, the enormous volume of data generated by microarray experiments has raised new issues regarding the sharing of microarray data beyond traditional peer-reviewed publication. We propose to create a Neuroscience Microarray Center to address these issues, and to increase access of the neuroscience community to DNA microarrays appropriate for analysis of gene expression in the nervous system. To increase the supply of DNA microarrays for neuroscience, the proposed center builds on the expertise of existing microarray core facilities with extensive experience in large-scale production and analysis of DNA microarrays. In concert with this array production component, the center will offer a formal course in the design, conduct and interpretation of microarray experiments, as well as ongoing advice to investigators. Research and development efforts will address two special requirements for neuroscience applications of DNA microarrays. First, we will develop DNA arrays with an enhanced ability to resolve major gene families involved in nervous system development, normal brain functions, and neurological diseases. Second, we will investigate best practices for the preparation of samples from defined nuclei, or identified populations of neurons. Particular emphasis will be given to determining optimal conditions for tissue processing and RNA extraction from human brain samples, and to an evaluation of alternative approaches for the isolation of small numbers of functionally or anatomically defined neurons. Finally, the proposed center will bring together experts in intellectual property law, research ethics, and neuroscience to address legal, ethical, and scientific aspects of microarray data sharing.